Throppers Posted July 14, 2019 Share Posted July 14, 2019 HiI have a Hornby Duchess Class 4-6-2 loco R2531 which runs fine in a forward direction but jams in reverse. I assumed a split gear however having removed / inspected all the gears, I can see nothing wrong with them. So I put the wheels back on with the idler gear removed so I can free spin the wheels and have noticed an issue with the front pair of wheels, which jam or pop out of the axle mounts when turned backwards. However when running forwards they are fine. The followong youtube video demonstrates. https://youtu.be/_pXhjK27KfYAny ideas?ThanksThroppers Link to comment Share on other sites More sharing options...
walkingthedog Posted July 14, 2019 Share Posted July 14, 2019 Are you sure the connecting rods aren’t fouling each other. Is the quartering OK. I think you’ll find the wheels will lift out of the chassis without the keeper plate in place and without any weight on them. Link to comment Share on other sites More sharing options...
Going Spare Posted July 14, 2019 Share Posted July 14, 2019 With the foam cradle not pressing on the motion, rotate the wheels and observe the movement of the various rods - as walkingthedog says, you will probably find one snagging on another on one side of the loco or the other. Possibly a connecting rod is being hit by the crank pin on the leading wheel. A little judicious bending of the rod should reinstate the clearance needed. Try free-wheeling the loco on a section of track as well. A quartering problem would probably manifest itself in both directions of travel. GS Link to comment Share on other sites More sharing options...
Throppers Posted July 14, 2019 Author Share Posted July 14, 2019 Hi all. Further video below to answer some points raised. https://youtu.be/xQatG-3eKp4Having checked all the rods and crank pins, everything is fine with no snagging or catching at all. Having pushed it along the track it runs along fine but this is a bit of a false test admin reality the drive comes from the centre axle and the front and rear axle are turned by the con-rods. Link to comment Share on other sites More sharing options...
Chrissaf Posted July 14, 2019 Share Posted July 14, 2019 Looking at the second video. I believe the 'quartering' on the far right wheel is very slightly out. This still is taken from the video where you are rotating the middle driver wheel 'clockwise' by hand just at the point that the front wheel starts to lift. You can see that the rod (marked in red) is not horizontal or better still just fractionally above horizontal at the right hand side, when compared to the left hand side connecting rod indicated by the green line. The right hand side is below the horizontal green centre line, thus the rotation forces being applied to the right hand wheel are trying to turn it 'anti-clockwise' against the position of the wheel on the opposite side (which presumably has the correct quartering....since we can't see it)..I believe that if you slightly rotate the right hand side wheel on the axle as indicated by the white arrow (keeping the opposite wheel fixed, so it can't turn on the axle). Just a slight rotation to bring the red marked rod up to a horizontally level position so that it is inline with the green line, then that may cure the jam..The reason that the wheel doesn't lift when the middle wheel is being turned 'anti-clockwise' is because the right hand side connecting rod is then in tension rather than compression, so that acts to pull the right hand side wheel axle back into the bearing seat../media/tinymce_upload/50d70c613dd4db9bf716e8e9c5fca40b.jpg.Of course, what I perceive to be a slight quartering error may just be as a result of the camera angle. But worth checking by looking at the loco more closely with a straight on side view to rule it in or out. Link to comment Share on other sites More sharing options...
Rog RJ Posted July 14, 2019 Share Posted July 14, 2019 Looks like the motion on the middle wheel, on the opposite side to the wheel that is jamming, is catching just at the point where the wheel locks. Link to comment Share on other sites More sharing options...
Throppers Posted July 14, 2019 Author Share Posted July 14, 2019 Chrisaff, thanks that’s really informative I will give that a go tomorrow and see if it helps. Link to comment Share on other sites More sharing options...
Throppers Posted July 15, 2019 Author Share Posted July 15, 2019 So late yesterday evening I remove the front axle to play with the quartering. Whilst I haven’t got it perfect yet, changing the quartering did worsen or lessen the issue to I’m happy it is related to the quartering. i quickly realised that the wheels are quite loose on the axle. It didn’t take much effort at all to turn the wheel on the axle so its worn and needs a new wheel set. The wheelset for this loco (Duchess Class) is X9090, however the Princess Class wheels (X9121M) are a lot cheaper. Can anyone advise if these are geometrically the same and therefore interchangeable (aesthetic appearance isn’t an issue) thanks Link to comment Share on other sites More sharing options...
Rog RJ Posted July 15, 2019 Share Posted July 15, 2019 Looking at the video again, you can quite clearly see that the wheel weights on one side don't line up, showing that the quartering isn't correct. Link to comment Share on other sites More sharing options...
Throppers Posted July 15, 2019 Author Share Posted July 15, 2019 The wheel weights are moulded off centre on one of the sets of wheels compared to the other, that’s normal. Link to comment Share on other sites More sharing options...
walkingthedog Posted July 15, 2019 Share Posted July 15, 2019 Yes it is. They are not always the same on all the wheels. Depended if some axles were crank shafts for inside cylinders. Link to comment Share on other sites More sharing options...
Throppers Posted July 15, 2019 Author Share Posted July 15, 2019 Yes it is. They are not always the same on all the wheels. Depended if some axles were crank shafts for inside cylinders. thanks. Just to confirm when you say “yes it is” you mean that it’s possible to interchange those Princess class and Duchess class wheel? Link to comment Share on other sites More sharing options...
walkingthedog Posted July 15, 2019 Share Posted July 15, 2019 I was answering your question regarding the weights. Yes it is normal. Do not adjust the quartering using the wheel weights as a guide as they may not be symmetrical, use the crank pins where the drive rods connect. Link to comment Share on other sites More sharing options...
Throppers Posted July 15, 2019 Author Share Posted July 15, 2019 I was answering your question regarding the weights. Yes it is normal. Do not adjust the quartering using the wheel weights as a guide as they may not be symmetrical, use the crank pins where the drive rods connect. Sorry, I see yes Link to comment Share on other sites More sharing options...
Throppers Posted July 18, 2019 Author Share Posted July 18, 2019 Problem solved!On trying to re-quarter the wheels it became clear that the axles were worn as the wheels turned on the axle too easily. New wheelset fitted (used the wheels from the Princess Class which are approx 1mm smaller but much cheaper and fit fine). Now runs smooth as butter! Link to comment Share on other sites More sharing options...
walkingthedog Posted July 18, 2019 Share Posted July 18, 2019 Well done, thanks for updating us. Link to comment Share on other sites More sharing options...
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